2. Baseline characteristics of participants included in meta‐analysis.
| Characteristic | Chalmers 2020 | Cooke 2015 | Dissanayake 2019 | Horimukai 2014 | Lowe 2018a | Migacheva 2018 | McClanahan 2019 | Simpson 2014 | Skjerven 2020 |
| Gestational age: mean (SD) | 40 (1.3) | 40 (1.3) | 39 (1.1) | 39.1 (1) | 39.3 (1.6) | ‐ | ‐ | 40.3 (1.3) | 39.3 (1.6) |
| Female: n (%) | 661 (47) | 49 (43) | 275 (50) | 50 (42) | 41 (51) | 29 (48) | 49 (49) | 41 (53) | 1134 (47) |
| Birth weight: mean grams (SD) | 3405 (452) | 3048 (322) | 3054 (363) | 3356 (442) | ‐ | ‐ | 3577 (480) | ||
| Vaginal delivery: n (%) | 954 (68) | 95 (83) | 420 (77) | 89 (75) | 31 (41) | ‐ | 80 (80) | 32 (26) | 1999 (83) |
| Age intervention began: mean days (SD) |
13 (10) | All < 3 | ‐ | 2 (2) | 12 (7) | ‐ | 13 (14) | 14 (6) | ‐ |
| Family history atopy: n (%) | 1394 (100) | 37 (79) | 457 (83) | 118 (100) | 80 (100) | ‐ | 100 (100) | 124 (100) | 1814 (78) |
| Filaggrin (FLG) (1/2 mutations): n (%) | 125 (15) | ‐ | ‐ | ‐ | ‐ | ‐ | 5 (9) | 17 (27) | ‐ |
| Sample size | 1394 | 115 | 549 | 118 | 80 | 60 | 100 | 124 | 2396 |
SD: standard deviation